JP7363439B2 - Walking aid device and its control method - Google Patents

Description

The present invention relates to a walking assist device and a control method thereof.

Patent Document 1 discloses a walking support device that assists walking motion. The walking support device includes an actuator and a one-way damper. The actuator applies a torque to the transtibial link. The one-way damper generates a resistance force against rotation in the direction of knee flexion, but does not generate resistance force against rotation in the direction of knee extension. The one-way damper is controlled to cycle through a free mode that allows free rotation, a damper mode that provides resistance, and a lock mode that prohibits rotation.

Patent No. 5316708

Since such a walking support device is fixed to a user's leg, it is desirable to reduce the size and weight of the device. Furthermore, it is desired to perform control to more appropriately assist walking motion.

The walking assist device according to the present embodiment is a walking assist device that is attached to a leg of a user, and includes a damper that applies a resistance force in a bending direction of a knee joint of the leg, and a switching timing in the walking cycle of the user. a sensor provided to detect the damper according to the switching timing so that the first mode and the second mode in which the resistance force is stronger than the first mode are alternately repeated. and a control section for switching the mode.

In the walking assist device described above, the damper may not be locked during the entire walking cycle.

In the walking assist device described above, the damper may be a one-way damper that is free in the direction of extension of the knee joint.

In the walking aid device described above, the sensor may measure the user's shin angle.

In the walking aid device described above, the sensor may measure a distance to a floor surface.

In the walking assist device described above, in the first mode, the damper may be free and the resistance force may be zero.

It is preferable that the walking assist device described above is not provided with an actuator that generates an assist force to the knee joint.

The above walking assist device may further include a transmitter that transmits the data acquired by the walking assist device to an external device.

The above-mentioned walking aid device may be provided with a solar cell that supplies power to the sensor or the control section, and a light receiving section of the solar cell may be provided on the surface of the walking aid device.

A method for controlling a walking assist device according to the present embodiment is a method for controlling a walking assist device attached to a leg of a user, wherein the walking assist device applies a resistance force in a bending direction of a knee joint of the leg. a damper that provides a damper, a sensor provided to detect switching timing in the user's walking cycle, and a control unit that switches the mode of the damper according to the switching timing, The second mode in which the resistance force is stronger than the first mode is controlled so that the second mode is alternately repeated.

In the above control method, the damper may not be locked during the entire walking cycle.

In the above control method, the damper may be a one-way damper that is free in the direction of extension of the knee joint.

In the above control method, the sensor may measure the user's shin angle.

In the above control method, the sensor may measure a distance to a floor surface.

In the above control method, in the first mode, the damper may be free and the resistance force may be zero.

In the above control method, it is preferable that the walking assist device is not provided with an actuator that generates an assist force to the knee joint.

In the above control method, the data acquired by the walking assist device may be transmitted to an external device.

In the above control method, the walking assist device is provided with a solar cell that supplies power to the sensor or the control section, and a light receiving section of the solar cell is provided on a surface of the walking assist device. Good too.

According to the present embodiment, it is possible to provide a walking assist device that can appropriately assist walking motion with a simple configuration, and a control method thereof.

1 is a perspective view showing a schematic configuration of a walking training system in which the walking assist device according to the present embodiment can be used. FIG. 1 is a front view showing a schematic configuration of a walking assist device. FIG. 1 is a side view showing a schematic configuration of a walking assist device. FIG. 2 is a block diagram showing a control system of the walking training device. FIG. 3 is a diagram for explaining a walking cycle and mode switching timing. It is a block diagram showing a control system of a walking training device concerning a modification.

The present invention will be described below through embodiments of the invention, but the claimed invention is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are essential as means for solving the problem. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant explanation will be omitted as necessary.

Embodiment 1.
The walking assist device according to the present embodiment is worn, for example, by a trainee who performs walking training. A trainee performs walking training while wearing a walking assist device. For example, a trainer who is a hemiplegic patient suffering from paralysis in one leg attaches a walking assist device to the affected leg, which is the paralyzed leg. In the following description, an example will be described in which a trainee who is a user performs walking training using a walking training system in the latter stage of rehabilitation. Note that the walking assist device may be used not only during walking training using the walking training system, but also when walking in a hospital, outdoors, or the like.

FIG. 1 is a schematic diagram illustrating the configuration of a walking training system to which a walking assist device according to the first embodiment is applied. As shown in FIG. 1, the walking training system 1 includes a walking assist device 2 attached to the leg of a trainee U, and a training device 3 for training the trainee U to walk. Note that the walking assist device 2 may be used for something other than the training device 3. In other words, the walking assist device 2 may be used alone. For example, the trainee U wearing the walking aid device 2 may perform walking training on stairs, on flat ground, on a slope, etc.

The walking assist device 2 is attached to, for example, the affected leg of a trainee U who performs walking training, and assists the trainee U in walking. A trainee U performs walking training with the walking assist device 2 attached to the knee joint. The walking assist device 2 applies a resistance force in the direction of bending the knee joint.

The walking assist device 2 will be explained using FIGS. 2 and 3. FIG. 2 is a front view of the walking assist device 2. FIG. 3 is a side view of the walking assist device 2.

The walking assist device 2 includes a supporter 21, a damper 22, an upper leg frame 23, and a lower leg frame 24. A short leg orthosis may be attached to the lower side of the walking aid device 2. The supporter 21 is made of a stretchable material such as a resin material or a fiber material. The supporter 21 is placed in and around the knee joint, specifically, from the upper leg to the lower leg. Note that the upper leg indicates the part from the hip joint to the knee joint, and the lower leg indicates the part from the knee joint to the ankle joint. The part below the ankle joint, that is, on the tip side, is the foot. The upper leg, lower leg, and foot are collectively referred to as the lower leg.

The supporter 21 has a hook-and-loop fastener 21a for attaching the walking assist device 2 to the knee joint. The trainee U wraps the supporter 21 around the leg and secures it with the hook-and-loop fastener 21a. The hook-and-loop fasteners 21a are provided above and below the knee joint, specifically, on the front side of the upper leg and the front side of the lower leg. By using the hook-and-loop fastener 21a, the trainee U can easily attach and detach the walking aid device 2. Furthermore, it is possible to prevent the walking assist device 2 from shifting from the knee joint of the trainee U. The hook-and-loop fastener 21a allows the trainee U to adjust the degree of compression. Furthermore, a fixing band may be provided to prevent the hook-and-loop fastener 21a from coming off and the supporter 21 from shifting.

An upper leg frame 23 and a lower leg frame 24 are attached to the sides of the supporter 21. The upper leg frame 23 is arranged along the upper leg. The lower leg frame 24 is arranged along the lower leg. Upper leg frame 23 and lower leg frame 24 are connected via damper 22. The damper 22 is, for example, a rotary damper, and is located on the side of the knee joint. Specifically, the damper 22 is arranged at the height of the knee joint so that the rotation axis Ax of the damper 22 substantially coincides with the axis of the knee joint. The upper leg frame 23 and the lower leg frame 24 constitute a link mechanism rotatable around the rotation axis Ax of the damper 22.

The damper 22 provides a resistance force in the direction of bending the knee joint. For example, the damper 22 uses viscous resistance of fluid such as oil to decelerate the rotation of the knee joint in the bending direction. It is preferable that the damper 22 is a one-way damper that applies resistance only in one direction. The damper 22 is free so as not to apply any resistance force in the direction of extension of the knee joint. As will be described later, the damper 22 can be switched by a switch.

Note that the fixation of the upper leg frame 23 and the lower leg frame 24 is not limited to hook and loop fasteners. For example, the upper leg frame 23 and the lower leg frame 24 may be fixed to the upper leg and lower leg using fixing means such as a belt, button, pin, or band. Even if such a fixing means is used, the trainee U can wear the walking assist device 2.

In addition, the structure of the walking assistance device 2 mentioned above is an example, and is not limited to this. The walking assist device 2 may be any device that is attached to the leg of the trainee U and has a damper 22.

Returning to the explanation of FIG. The training device 3 includes a treadmill 31, a frame body 32, a control device 35, and a display section 36. The treadmill 31, the control device 35, and the display section 36 are fixed to the frame body 32. The display unit 36 is arranged in front of the trainee U.

The treadmill 31 has a rotatable ring-shaped belt conveyor 311 for the trainee U to walk on, and rotates the belt conveyor 311 at a set speed Vs. The trainee U rides on the belt conveyor 311 and walks according to the movement of the belt conveyor 311. The display unit 36 displays information such as training instructions for the trainee U, a training menu, and training information (setting speed, biological information, etc.). For example, the display unit 36 may include a touch panel, in which case the trainee U can input various information via the display unit 36. Further, the training device 3 may include a camera that images the trainee U, or the like. Thereby, the display unit 36 can display an image of the walking motion of the trainee U during training.

The control device 35 includes, for example, a CPU (Central Processing Unit) that performs arithmetic processing, control processing, etc., a ROM (Read Only Memory) that stores arithmetic programs executed by the CPU, control programs, etc., and stores various data. The hardware is mainly composed of a microcomputer, which includes a RAM (Random Access Memory), an interface section (I/F) that inputs and outputs signals to and from the outside, and the like. The CPU, ROM, RAM, and interface section are interconnected via a data bus or the like.

FIG. 4 is a block diagram showing a control system of the walking assist device 2 according to this embodiment. The walking aid device 2 includes a damper 22, a sensor 4, and a switch 28.

The damper 22 provides a resistance force in the bending direction of the knee joint as described above. The switch 28 switches the mode of the damper 22. For example, a solenoid switch or the like can be used as the switch 28. The switch 28 switches the mode of the damper 22 so that the damper 22 alternately switches between the first mode and the second mode. In the first mode, the damper 22 is turned off, resulting in a free mode in which no resistance is applied in the bending direction. In the second mode, the damper 22 is turned on and becomes a damper mode that provides resistance in the bending direction.

The sensor 4 detects the timing of the trainee U's walking motion. Specifically, the sensor 4 is provided to detect switching timing in a walking cycle. The switch 28 switches the mode based on the detection result from the sensor 4. That is, based on the timing signal output from the sensor 4, the solenoid switch that is the changeover device 28 is controlled to be on/off. Thereby, the switch 28 switches the mode of the damper 22 at a certain timing in the walking cycle. Power is supplied to the sensor 4 and the switch 28 by a battery (not shown) mounted on the walking aid device 2 .

FIG. 5 is a diagram showing the walking motion in one walking cycle and the timing of mode switching. Note that one walk cycle includes a total of two steps: one step with the left leg and one step with the right leg. In FIG. 5, one walking cycle is shown in the order of (a) to (m). After the timing (m), the process returns to the timing (a), and the next walking cycle begins. In FIG. 5, the swing phase occurs at timings (a) to (g), and the stance phase occurs at timings (h) to (m). The sole of the foot touches the ground between the timing of (g) and (h), and the sole of the foot leaves the ground at the timing of returning from (m) to (a). Timings (a) to (c) are the flexion period when the flexion angle of the knee joint is increasing, and timings (d) to (g) are the extension period when the flexion angle of the knee joint is decreasing. There is. Note that the swing phase, stance phase, flexion phase, and extension phase are based on the affected leg wearing the walking aid device 2.

In this embodiment, during the extension period, specifically, the first mode is switched to the second mode at the timing (f). Moreover, the second mode is switched to the first mode at the timing when the stance phase changes to the swing phase, specifically, between the timing (m) and the timing (a). During the swing phase, there is no need for the affected leg to support the weight of the trainee U. Therefore, there is no need for the damper to generate a resistance force against the knee joint, and the damper can be free in the bending direction during almost the entire swing phase. In other words, the damper 22 is in the second mode in which it generates a resistance force in the bending direction during the entire stance phase.

Furthermore, only a first mode in which the damper is free in one walking cycle and a second mode in which a resistance force is generated are provided, and the switch 28 switches between the first mode and the second mode alternately during the walking motion. Switching. In other words, the switch 28 controls the damper 22 on and off based on the timing signal. By doing so, appropriate control can be performed with a simple configuration. For example, if the walking motion varies from walk cycle to walk cycle, the switching timing detected by the sensor 4 may vary. Even in such a case, it is sufficient that the damper 22 is switched from the first mode to the second mode at a timing before switching from the swing phase to the stance phase, that is, at an arbitrary timing during the extension phase.

Specifically, it is sufficient that the switch 28 switches the mode between (d) and (g). Since the margin for the error in the switching timing detected by the sensor can be widened, appropriate control can be achieved. Furthermore, during the extension phase, the knee joint gradually rotates from a flexed state in the direction of extension. Therefore, even if the damper 22 is in the second mode, no resistance force is generated. Therefore, the mode can be switched without the damper 22 interfering with the walking motion of the trainee U.

Furthermore, in the extension direction, the damper is free during the entire walking cycle, so the trainee U can freely extend the knee joint. Moreover, since there is no lock mode in which the damper 22 is locked between the damper mode and the free mode, it is possible to prevent the damper 22 from interfering with walking motion. Since the second mode is transferred to the first mode without going through the lock mode, appropriate control can be easily performed.

In addition, in the above description, mode switching between the first mode and the second mode is performed by the switching device 28 controlling the damper 22 on/off, but mode switching control is limited to on/off control. It's not a thing. The resistance force of the damper 22 may be gradually increased or decreased at the timing of mode switching. For example, a period may be provided between the first mode and the second mode in which the resistance force gradually changes. For example, the resistance force may be increased or decreased in steps when switching between the first mode and the second mode.

Further, the first mode is not limited to the free mode of the damper 22. For example, it is sufficient that the resistance force of the damper 22 in the first mode is lower than the resistance force of the damper 22 in the second mode. Therefore, in the first mode, the damper 22 may or may not generate a resistance force.

The switching timing between the swing phase and the stance phase may be detected by the output of the sensor 4, and the swing phase may be set to the first mode and the stance phase may be set to the second mode. In other words, the timing of changing from the swing phase to the stance phase and the timing of switching from the stance phase to the swing phase may be used as the timing for switching the mode of the damper 22. The switch 28 serves as a control unit that alternately switches between the first mode and the second mode.

Further, the walking assist device 2 does not require an actuator for generating a resistance force to the knee joint. In other words, there is no need for an assist motor or actuator, and the walking assist device 2 can be made lighter and smaller. Furthermore, by using an oil damper or the like having a passive configuration, it becomes easier to follow the walking motion of the trainee U, and control becomes easier.

Furthermore, the walking assist device 2 may be equipped with a battery for supplying power to the sensor 4 and the switch 28 . Since a solenoid switch with low power consumption is mounted as the switch 28, power can be supplied to the switch 28 and the sensor 4 even when a low capacity battery is used. Therefore, the battery can be made lighter and smaller. The battery may be a rechargeable/dischargeable secondary battery or a primary battery. Further, the battery may be a solar cell. In this case, it is sufficient that a light receiving section of a solar cell is provided on the surface of the walking aid device 2. Further, the switch 28 may include a switch other than a solenoid switch. For example, the switch 28 may include a switch such as a semiconductor switch. The switch 28 may be configured to switch the mode of the damper 22 by controlling ON/OFF switching of a switch using a control signal from an electronic circuit. Further, by using a solenoid switch as a control section for switching modes, it is possible to achieve a reduction in size and weight.

(Specific example of sensor 4)
As the sensor 4, various types of sensors can be used. A specific example of the sensor 4 will be described below.

As the sensor 4, an angle sensor that detects the shin angle (lower limb angle) or an angular velocity sensor that detects the angular velocity of the shin (lower limb) can be used. An angle sensor or an angular velocity sensor attached to the lower leg frame 24 can be used as the sensor 4. The sensor 4 measures the shin angle because the shin angle changes depending on the timing in the walking cycle. The detection result of the shin angle shows a waveform according to the walking cycle. In other words, the shin angle changes periodically according to the walking cycle. Walking timing can be detected based on the shin angle measured by the sensor 4.

For example, the output value of the sensor 4 may be compared with a threshold value, and the mode of the damper 22 may be switched according to the comparison result. For example, mode switching is performed in response to a timing signal indicating the timing at which the output value of the sensor 4 exceeds a threshold value or falls below a threshold value. Note that a first threshold value for detecting the switching timing for switching from the first mode to the second mode and a second threshold value for detecting the switching timing for switching from the second mode to the first mode may be set. .

Alternatively, as the sensor 4, a distance sensor that measures the distance to the floor (for example, the belt conveyor 311 of a treadmill) can be used. For example, a distance measuring sensor attached to a shoe, a foot, or the vicinity thereof can be used as the sensor 4. Since the distance from the sole of the foot to the floor changes depending on the walking motion, the waveform shows a waveform that corresponds to the walking cycle. In other words, the distance from the sole of the foot to the floor changes periodically according to the walking cycle. Therefore, by using a distance measuring sensor as the sensor 4, the walking timing can be detected. For example, the output value of the sensor 4 may be compared with a threshold value, and the mode of the damper 22 may be switched according to the comparison result. An optical sensor can be used as the distance measurement sensor.

Further, the switching timing may be detected by combining a plurality of sensors 4. For example, the sensor 4 may include both a first sensor provided to detect the shin angle and a second sensor provided to detect the distance from the sole of the foot to the floor surface. Of course, the specific example of the sensor 4 is not limited to the above example. Preferably, the sensor 4 is mounted on the walking aid device 2. Alternatively, the sensor 4 may be mounted outside the walking aid device 2. For example, the sensor 4 may be a camera, a depth sensor, a distance sensor, etc. attached to the training device 3. When the sensor 4 is provided externally, the walking assist device 2 only needs to include a receiving section that receives a signal indicating the switching timing from the external sensor 4.

Modification Example Hereinafter, a modification example of the walking assist device according to the present embodiment will be described using FIG. 6. FIG. 6 is a block diagram showing a control system of the walking assist device 2 according to a modification. In FIG. 6, the walking assist device 2 includes a calculation device 51, a memory 52, a transmitter 53, and a receiver 54 in addition to the configuration shown in FIG. Note that the damper 22, the switch 28, and the sensor 4 are the same as those in the first embodiment, so their explanations will be omitted.

The arithmetic unit 51 includes, for example, a CPU (Central Processing Unit) that performs arithmetic processing, control processing, etc., a ROM (Read Only Memory) that stores arithmetic programs executed by the CPU, control programs, etc., and stores various data. It is composed of hardware centered on a microcomputer, which includes a RAM (Random Access Memory) for data processing, an interface unit (I/F) for inputting and outputting signals with the outside, and the like. The CPU, ROM, RAM, and interface section are interconnected via a data bus or the like.

The output value from the sensor 4 is input to the calculation device 51 . The calculation device 51 detects the switching timing in the walking cycle by performing predetermined calculation processing on the output value of the sensor 4. For example, the calculation device 51 detects the switching timing by comparing the output value of the sensor with a threshold value. When the arithmetic device 51 outputs the switching timing to the switch 28, the switch 28 switches the mode of the damper 22. The memory 52 stores data of output values from the sensor 4 during walking training.

A switching signal indicating that the mode has been switched from the switch 28 may be input to the arithmetic device 51. The arithmetic device 51 counts switching operations of the switch 28 based on the switching signal. The arithmetic device 51 counts the switching operations of the switch 28 and writes the number of switching operations into the memory 52 . The number of times the switch 28 is switched corresponds to the number of steps. By doing so, the number of steps taken during walking training can be counted without separately wearing a pedometer (registered trademark) or the like. Therefore, convenience can be improved. Furthermore, the number of steps during walking training can be counted without adding a separate sensor for counting steps. Therefore, compared to a configuration in which a sensor for counting steps is separately added, the cost and weight of the walking assist device 2 can be reduced.

The transmitter 53 transmits data to an external device, such as the control device 35 or an external server. The receiving unit 54 receives data from an external device. The transmitter 53 and the receiver 54 transmit and receive data according to a communication standard such as Bluetooth (registered trademark), for example. Communication between the transmitter 53 and the receiver 54 may be wireless communication or wired communication.

The transmitter 53 transmits data acquired by the walking assist device 2, such as the output value of the sensor 4 during walking training and the number of times the switch 28 is switched, to an external device. This allows the external device to collect data. Therefore, it becomes possible to cooperate with external devices and reduce the capacity of the memory 52. Furthermore, the transmitter 53 may automatically transmit the output of the sensor 4 during training.

The receiving unit 54 receives data from an external device, for example, the control device 35. Thereby, the detection conditions for walking timing can be changed. Specifically, settings such as a threshold value for detecting switching timing can be changed. For example, when changing the threshold setting, the control device 35 may transmit a command to change the threshold setting. When the receiving unit 54 receives a setting change command, the arithmetic unit 51 changes the threshold value. Optimal detection conditions can be set for each user. Thereby, optimal detection conditions can be set for each user.

For example, the transmitter 53 transmits the output value of the sensor to the control device 35. A display unit 36 or the like displays a periodic waveform of the sensor output. A training assistant such as a physical therapist can set the threshold by operating an input device such as a touch panel, keyboard, switch, or mouse while checking the waveform of the sensor output.

Note that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit.

1 Walking training system 2 Walking assistance device 3 Training device 4 Sensor 21 Supporter 22 Damper 23 Upper leg frame 24 Lower leg frame 28 Switch 31 Treadmill 32 Frame body 35 Control device 36 Display section 311 Belt conveyor 51 Arithmetic device
52 Memory 53 Transmitter 54 Receiver U Trainer

Claims (12)

A walking aid device that is attached to a user's leg,
a damper that applies a resistance force in the bending direction of the knee joint of the leg;
a sensor provided to detect switching timing in the user's walking cycle;
The damper is operated in accordance with the switching timing so that a first mode in which the damper does not apply the resistance force and a second mode in which the resistance force is stronger than the first mode are alternately repeated. Equipped with a switch that changes the mode,
The walking assist device is not provided with an actuator that generates an assist force to the knee joint,
The damper is a one-way damper that is free in the direction of extension of the knee joint,
The sensor is a distance sensor that is attached to a shoe or a foot and measures the distance to the floor,
The switching timing is detected according to a comparison result of comparing the output value of the sensor with a threshold value,
The walking assist device is configured to switch between the first mode and the second mode by controlling the switch to turn on and off based on a timing signal indicating the switching timing. The walking aid device according to claim 1, wherein the damper does not lock during the entire walking cycle. Based on a comparison result between the output value of the sensor and a first threshold value, a switching timing from the first mode to the second mode is detected;
The walking assist device according to claim 1 or 2, wherein the timing of switching from the second mode to the first mode is detected based on a comparison result between the output value of the sensor and a second threshold value. The walking assist device according to any one of claims 1 to 3, wherein in the first mode, the damper becomes free and the resistance force becomes zero. The walking assist device according to any one of claims 1 to 4, further comprising a transmitter that transmits the data acquired by the walking assist device to an external device. The walking assist device is provided with a solar cell that supplies power to the sensor or the switch ,
The walking assist device according to any one of claims 1 to 5, wherein the light receiving section of the solar cell is provided on the surface of the walking assist device. A method for controlling a walking aid device worn on a user's leg, the method comprising:
The walking assist device includes a damper that applies a resistance force in the bending direction of the knee joint of the leg;
a sensor provided to detect switching timing in the user's walking cycle;
a switch that is a switch that switches the mode of the damper according to the switching timing;
controlled so that a first mode in which the resistance force is not applied by the damper and a second mode in which the resistance force is stronger than in the first mode are alternately repeated;
The walking assist device is not provided with an actuator that generates an assist force to the knee joint,
The damper is a one-way damper that is free in the direction of extension of the knee joint,
The sensor is a distance sensor that is attached to a shoe or a foot and measures the distance to the floor,
The switching timing is detected according to a comparison result of comparing the output value of the sensor with a threshold value,
A method for controlling a walking assist device, wherein the first mode and the second mode are switched by controlling the switch on and off based on a timing signal indicating the switching timing. 8. The method of controlling a walking assist device according to claim 7 , wherein the damper does not lock during the entire walking cycle. Based on a comparison result between the output value of the sensor and a first threshold value, a switching timing from the first mode to the second mode is detected;
The method of controlling a walking assist device according to claim 7 or 8, wherein the timing of switching from the second mode to the first mode is detected based on a comparison result between the output value of the sensor and a second threshold value. 10. The method of controlling a walking assist device according to claim 7 , wherein in the first mode, the damper becomes free and the resistance force becomes zero. The method for controlling a walking assist device according to any one of claims 7 to 10, wherein the data acquired by the walking assist device is transmitted to an external device. The walking assist device is provided with a solar cell that supplies power to the sensor or the switch ,
12. The method of controlling a walking assist device according to claim 7, wherein the light receiving section of the solar cell is provided on the surface of the walking assist device.

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